Defense activities often include attacking of enemy targets using guided projectiles or missiles. During storage and handling prior to launch, the missile is usually kept in a missile container, which also serves as a launching tube. While the missile is in the missile container, it is connected by an electric cable with the missile container and a control unit for the missile. This cable transmits electric signals to the missile while the missile is in storage to test its various functions. When the missile is used in field service, this cable transmits the necessary starting signals to the missle. When the missile has been started, this cable connection must be broken in such a way that, after said breaking, no remnants of the cable will be dragged along by the missile. Because of the high velocity of the missile, its aerodynamic properties are seriously affected if the contact device in the missile has an influence on the air flow around the missile, which is smooth in other respects.
In the missiles available in the market, two kinds of separating mechanisms are known for breaking the electric cable connection. One kind consists of extractable contact devices; and the other, of so-called guillotine devices for the cable.
The extractable contact device usually consists of a connection by contacts made between the missile and the missile container. The contact device is placed at the rear of the missile in such a way that male and female contacts are located axially parallel to the axis of the missile. When the missile is launched and moves forward in the missile container, the male contact will automatically be pulled out of the female contact, thereby breaking the connection between the missile and the missile container. Such contact devices are not suitable for use in missiles equipped with a separate booster motor which can be jettisoned in flight. If such a contact device is used, in this case, a further contact connection must be provided between the booster motor and the rear surface of the missile. The further contact is broken when the booster motor is jettisonal.
The guillotine devices consist essentially of two nonconductive plates which can slide in relation to each other, and are provided with through holes at right angles to the direction in which they slide. The cable between the missile and the missile container can be passed through one such hole, or specific electrical conductors in the cable can be passed through separate holes. When the missile is started and the electric cable connection is to be broken, one of the plates is caused to move in relation to the other one, for instance by means of an electrically activated powder activator, thereby breaking electrical connection.
Both of these previously known devices, particularly with respect to small missiles, have the disadvantage that they take up too much space and are too heavy in relation to the other parts of the missile. Moreover, for the guillotine devices, a separate electric impulse is required to carry out the electrical separation. For male-female contacts which are pulled out when the missile starts, no special separating signal need be transmitted, but such contacts have the disadvantage that they must be placed at the rear of the missile.